feat(platform): add slack platform support (#385)

* feat(platform): add slack platform support

* docs: add slack channel setup guide

* feat: normalize slack unicode reactions

* chore(docs): remove unsupport feature

* fix(slack): harden adapter stream and identity handling

- ignore reaction and speech stream events in Slack outbound
  streams
  - normalize Slack conversation types to framework-standard values
  - route DiscoverSelf through the adapter API factory
  - add config-scoped Slack user display-name caching
  - expand adapter interface assertions and add regression coverage
  - add ChannelTypeSlack to well-known channel constants

docs/docs/.vitepress/en.ts

@@ -175,6 +175,10 @@ export const en = [
         text: 'WeChat Official Account',
         link: '/channels/wechatoa.md'
       },
+      {
+        text: 'Slack',
+        link: '/channels/slack.md'
+      }
     ]
   },
 ]

docs/docs/channels/index.md

@@ -4,6 +4,7 @@ Channels are the gateways that connect your Memoh Bots to the outside world. By
 
 Memoh currently supports the following channels:
 
+- **[Slack](./slack)**: Workspace messaging with Socket Mode, threads, files, and reactions.
 - **[Telegram](./telegram)**: Feature-rich integration with streaming and attachment support.
 - **[Feishu (Lark)](./feishu)**: Enterprise-ready integration for business workflows.
 - **[Discord](./discord)**: Community-focused integration for servers and direct messages.

docs/docs/channels/slack.md

@@ -0,0 +1,84 @@
+# Slack Channel Configuration
+
+Connecting your Memoh Bot to Slack allows it to receive direct messages, participate in channels and threads, read attachments, send files, and use streaming replies.
+
+## Step 1: Create a Slack App
+
+1. Go to the Slack API dashboard and create a new app.
+2. Choose the workspace where you want to install the bot.
+3. Open **Basic Information** and keep this app page open for the next steps.
+
+## Step 2: Enable Socket Mode
+
+Memoh's Slack adapter uses Socket Mode, so you need an app-level token in addition to the bot token.
+
+1. In **Basic Information**, enable **Socket Mode**.
+2. Create an **App-Level Token** with the `connections:write` scope.
+3. Copy the generated token. It starts with `xapp-`.
+
+## Step 3: Configure Bot Token Scopes
+
+In **OAuth & Permissions**, add the bot token scopes required by the current Slack adapter:
+
+- `app_mentions:read` - receive bot mentions in channels
+- `channels:history` - read messages in public channels
+- `groups:history` - read messages in private channels
+- `im:history` - read direct messages
+- `mpim:history` - read group direct messages
+- `chat:write` - send replies and thread messages
+- `files:read` - read uploaded files and images
+- `files:write` - upload outbound files
+- `reactions:write` - add and remove reactions
+
+You should also add these recommended scopes if you want Slack conversation names and metadata to show up more completely in Memoh:
+
+- `channels:read`
+- `groups:read`
+- `im:read`
+- `mpim:read`
+
+## Step 4: Subscribe to Bot Events
+
+In **Event Subscriptions**, enable bot events and add:
+
+- `app_mention`
+- `message.channels`
+- `message.groups`
+- `message.im`
+- `message.mpim`
+
+These are the inbound event types currently handled by the Slack adapter.
+
+## Step 5: Install the App to Your Workspace
+
+1. In **OAuth & Permissions**, click **Install to Workspace**.
+2. Review the permission screen.
+3. Authorize the app.
+4. Copy the **Bot User OAuth Token**. It starts with `xoxb-`.
+
+Make sure the `xoxb-...` bot token and the `xapp-...` app-level token come from the same Slack app and workspace.
+
+## Step 6: Configure Memoh
+
+1. Open your Bot detail page in the Memoh Web UI.
+2. Go to the **Platforms** tab.
+3. Click **Add Channel** and select **Slack**.
+4. Fill in:
+   - **Bot Token**: your `xoxb-...` token
+   - **App-Level Token**: your `xapp-...` token
+5. Click **Save and Enable**.
+
+## Step 7: Add the Bot to Conversations
+
+After the channel is enabled, the Slack app still needs to be present in the conversations where you want it to work.
+
+- For direct messages: open a DM with the app and send a message.
+- For public channels: invite the bot to the channel.
+- For private channels: invite the bot explicitly after installation.
+
+If the bot can send messages but cannot read uploaded images or files, check that `files:read` is enabled. If it connects but receives no incoming messages, check the bot events and the matching history scopes again.
+
+## Features Supported
+
+- **Direct Messages and Channels**: Support for DMs, public channels, private channels, and threads.
+- **Attachments**: Read uploaded images and files from Slack, and send files back.

docs/docs/getting-started/channels.md

@@ -26,6 +26,7 @@ Configure your bot's connections from the **Platforms** tab in the Bot Detail pa
 | WeCom (WeWork) | [WeCom Configuration](/channels/wecom) | Enterprise workspace integration |
 | WeChat | [WeChat Configuration](/channels/weixin) | Personal QR login flow |
 | WeChat Official Account | [WeChat Official Account Configuration](/channels/wechatoa) | Official account webhook flow |
+| Slack |  [Slack Configuration](/channels/slack) | Replies, no streaming |
 
 Two WeChat adapters exist on purpose: